A liquid crystal display (LCD) is a kind of flat panel display (FPD) which displays images by the property of the liquid crystal material. In comparison with other display devices, the LCD has the advantages in lightweight, compactness, low driving voltage and low power consumption, and thus has already become the mainstream product in the whole consumer market. However, the liquid crystal material of the LCD cannot emit light by itself, and must depend upon an external light source. Thus, the LCD further has a backlight module to provide the needed light source.
Generally speaking, backlight modules have been developed based on size requirements into edge lighting type structures and bottom lighting type structures, which are categorized by locations of lamp tubes thereof. A light source of the edge lighting type structures is a single light source placed aside, and a light source of the bottom lighting type structures is placed right beneath. The lamp tubes of the backlight modules must be featured with high brightness and a long lifespan, etc., and include cold cathode fluorescent lamps (CCFL), hot cathode fluorescent lamps, light emitting diodes (LED) and electroluminescence (EL), etc. Nowadays, with the rise of environmental consciousness, because that using LEDs as backlight sources has an advantage of energy saving and environmental protection in comparison with the CCFL, it thus becomes a trend in backlight development to replace the CCFL by the LEDs. Besides, by using LEDs as a backlight source, an LCD or LCD TV is further developed toward a design direction of narrow frame.
Referring now to FIG. 1, a cross-sectional side view of a traditional liquid crystal module is illustrated in FIG. 1. Specially explaining, for conveniently describing, the contents of this figure are shown with a simple and schematic method. A traditional liquid crystal module 90 comprises a back plate 91, a light guide plate and optical film assembly 92, a plastic housing 93, a liquid crystal panel 94 and a front frame 95. The back plate 91 is used for loading light sources (not shown) and the light guide plate and optical film assembly 92; the plastic housing 93 is disposed on an outer side of the back plate 91 downward from top to bottom, and fix the light guide plate and optical film assembly 92 to form a backlight module; the liquid crystal panel 94 is loaded on the plastic housing 93; and the front frame 95 fixes the liquid crystal panel 94 on the backlight module. However, in the assembly of the liquid crystal module 90, it is necessary to use a method of screw-connection to assemble the liquid crystal module 90 or fix whole of the liquid crystal module 90 into an outer housing of an LCD. It will occupy an extra volume in the liquid crystal module 90 whether the screw members are disposed in a perpendicular or horizontal direction. Besides, it will increase the assembly steps, and is disadvantageous for a development trend that LCD is designed toward narrow frame.
As a result, it is necessary to provide an engaged type liquid crystal module to solve the problems existing in the conventional technologies.